The number of people using the Internet from their home continues to increase. As the number of users increases, there is greater interest in increasing the speed of Internet Protocol (IP) data transport, which would reduce the amount of time required to access Internet sites and the amount of time spent waiting for files to download. Most Internet users currently use a twisted pair telephone line to access an Internet Service Provider (ISP), which provides access to the Internet. The bandwidth of a subscriber television system allows faster transport of IP data than existing twisted pair telephone lines. As a result, many Internet users are interested in switching to the subscriber television system as the IP data transport service becomes available. Subscriber television system operators provide IP data connections because they provide additional revenue.
Current systems for transporting IP data over subscriber television systems dedicate a fixed and separate portion of the bandwidth to each Internet user. Dedicating a portion of the bandwidth to each Internet user provides a continuous data path for each user. Fixing a portion of the bandwidth provides every Internet user with a standard sized portion of the available bandwidth. Assigning the IP data to IP-only channels or communications paths isolates the IP data from the data associated with other services provided on the subscriber television system. IP-only channels often use unique formats for the IP data. The Data Over Cable Service Interoperability Specification (DOCSIS) standard is an example of a current system that dedicates a fixed and separate portion of the bandwidth to each user.
Dedicating a fixed and separate bandwidth for each Internet user can strain the resources of an IP data transport system as a subscriber television system adds additional Internet users. While digital applications expand the amount of information that can flow through the bandwidth of a subscriber television system, there is still only so much bandwidth, which must carry television programming and other services in addition to IP data. As Internet users request access, the system assigns a fixed standard size portion of the bandwidth to each user regardless of each user's particular requirements. The operator of a subscriber television system sets a maximum amount of bandwidth for IP data transport. Once the amount of bandwidth reserved for IP data transport reaches that maximum, the system denies the next request for Internet access. The subscriber television operator then has to deal with the customer dissatisfaction resulting from the denied access.
An additional impact of dedicating bandwidth to each Internet user is that there are large periods of time when a user is reading information and not transmitting or receiving IP data. The bandwidth remains dedicated to each user even when it is not being used. This is an inefficient use of bandwidth. There are typically a large number of users reviewing material and not actively using the dedicated bandwidth. Once the system reaches the maximum bandwidth reserved for IP data transport it starts denying access. This results in the subscriber television system denying access to additional users because all of the allotted bandwidth has been allocated, even if it is not being used.
As mentioned above, current systems use a separate portion of the bandwidth to transport the IP data. Current systems use special IP data channels or out-of-band signals. This isolates the IP data from the other services. Accessing isolated IP data requires additional equipment at the headend, subscriber location, or both. For example, to access an IP data channel while a subscriber is tuning to a regular television channel requires a separate tuner for the IP data channel. It is even more complicated in systems that format the IP data differently than the other services. Systems using different formats often require additional equipment in the headend and at the subscriber location. DOCSIS is an example of a system that requires separate equipment in the headend and a separate tuner at the subscriber location. This additional equipment is an extra expense for a subscriber television system operator or subscriber.
Thus, there is a need for an IP data transport system that makes efficient use of the bandwidth and uses the existing structure and equipment of the subscriber television system. Such an efficient system should allow several levels or types of IP data service based on different types of IP data users.